The Senate race between Kyrsten Sinema and Martha McSally remained too close to call Wednesday as the unexpected flood of voters left more than 650,000 ballots statewide left to count, further ratcheting up the tension in the contentious race.

Only a small fraction of votes separated the candidates, with McSally ticking ahead with 99 percent of precincts counted, according to the Secretary of State’s website. The total votes counted reached more than 1.7 million as of Wednesday afternoon, including votes for the Green Party candidatewho dropped out of the race last week.

Election officials said it likely will be at least Thursday before unofficial vote tallies for the McSally-Sinema race are in, as officials have to count ballots from remaining precincts, provisional ballots and “late early” ballots – those that were dropped off at the polls.

In Maricopa County, the state’s most populous, about 475,000 ballots need to be counted, according to Garrett Archer, a senior analyst with the Arizona Secretary of State’s Office.

Archer said early ballots have become a robust tradition in Arizona. He said “late early” ballots, which don’t get counted on Election Day, now are undergoing a signature-verification process.

“They’re essentially processing what is three or four days of early ballots as soon as possible … this is pretty standard for state general elections,” he said, adding that the count also involves a detailed review of provisional ballots.

“The counties set up teams that do the research for these provisional ballots, just to ensure the person who filled out the ballot is who they say they are,” Archer said. “It’s just one extra step.”

While they wait, Sinema, the Democrat, and McSally, the Republican, are staying out of the public spotlight. That’s a shift from a race that drew national attention for its tense battle between two candidates vying to be Arizona’s first female senator.

Arizona has not had a Democratic senator since Dennis DeConcini retired in 1995, and it has never sent a woman to the Senate in the state’s 106 years.

Neither McSally nor Sinema spoke to supporters at their respective watch parties Tuesday night. Organizers told crowds to leave about 11 p.m. after it became apparent no clear winner would be decided. Calls to both campaigns Wednesday were not returned.

Election-result delays are hardly new for Arizona. In 2012, Colorlines.com spoke with a representative for the Secretary of State’s Office, who blamed “late early” ballots, the kind where an early ballot is dropped off on Election Day, as a cause of the slowdown.

According to the report, results for some races in 2004, 2008 and 2012 took weeks to be verified.

The new senator will replace outgoing Sen. Jeff Flake, a two-term Republican who made headlines verbally tackling President Donald Trump. Flake announced his retirement in October 2017, setting off a three-candidate Republican primary to replace him.

The race had been viewed as one of the best chances for Democrats to shift the balance in Senate. But after Tuesday’s election results from other states appeared to give Republicans a Senate gain of three seats, Arizona is the last state where Democrats still have a chance to pick up a seat.

Healthcare continues to be one of the fastest rising costs for both employers and employees in the U.S. According to a June PricewaterhouseCoopers report, healthcare costs are expected to rise another 6 percent in 2019, with many of these costs being absorbed by employees.

Six parcels of Arizona State Trust Land appraised at a combined $14.26 million were set for auction by the Arizona State Land Department this month. Five of the parcels are near Tucson, one is in Phoenix, and all together total 81 acres of land.